Characterization of Forest Biodiversity Using the Point-Quarter Method
The study of biodiversity, the variability of the organisms throughout an environment, is a vital aspect of biological research (Russell et al, 2014). Forest biodiversity is currently disrupted with deforestation, creating issues such as increased greenhouse emissions (Russell et al, 2014). According to the Earth Policy Institute, about 31% of the world is covered in forests, but that number is drastically decreasing, making forest conservation a priority globally (Forest Resources Assessment, 2010). While protection is an important environmental factor, classification of a forest to maintain diversity is another aspect ecologists research (Biology 214 Laboratory Handout, 2013). Characteristics will be collected in this biodiversity study to accurately estimate the tree population on Case Western’s University Farm (Biology 214 Laboratory Handout, 2013).
Plenty of the current forest mapping relies highly on technological advancements. Even back in 1994, the United States Department of Agriculture started to utilize Advanced Very High Resolution Radiometer (AVHRR) and Landsat Thematic Mapper (TM) data to better map the forest density through 48 states (Zhu, 1994). The AVHRR and TM data is plotted to fit a regression that can accurately estimate the forest density it an area. Due to the technology being in its early years, the research ran into issues, specifically pertaining to the misinterpretation of small bodies of water and larger non-forest plants as forests (Zhu, 1994). Overall, the AVHRR and TM data was able to start the use of technology for forest density mapping on such a large scale, even with its limitations (Zhu, 1994).
How it works
While forest density mapping has become much more accurate, there are instances where technology is unavailable or will not provide all the data necessary for the researchers. In this experiment, the characteristics of tree density, species, and size are all things that can be collected through field research (Biology 214 Laboratory Handout, 2013). By utilizing the point-quarter sampling method, the Manor House wood lot will be estimated accurately. I predict the species of trees will be vast throughout the entire forest, but the data collected in smaller portions will have the same few species throughout, due to the seedlings usually taking root near the parent trees.
Materials and Methods (Biology 214 Laboratory Handout, 2013)
Materials: Measuring tape, binocular, pencil, clipboard, tree field guide
At the Manor House wood lot, teams of four researchers were split up and surveyed a different areas of the forest. For each individual group, a random spot was chosen as the sample point. From the sample point, the surrounding area was divided into four quadrants. In each of the quadrants, the three closest trees were characterized. The following measurements were taken for each tree: diameter (taken at breast height), the tree species, and the distance from the sample point (using steps to count). It is best to use the same person to measure either the diameter or distance so that the measurements are as standard as possible. A large data collection is best, so the measurements done by the other groups can be shared for the analysis. The overall goal is to determine the biodiversity in Manor House wood lot, which can be quantified through calculations. The importance value of each tree species can numerically determine the diversity throughout the wood lot through relative density, frequency, and dominance.
Importance Value=Relative Density+Relative Frequency+Relative Dominance
The relative dominance is important to see how much a species covers in comparison to the entire forest coverage (Mitchell, 2015).
Relative dominace= (Cross Sectional Area of Tree (Species A))/(Cross Sectional Area of All Trees)*100
The relative frequency is calculated by the dispersion of species A throughout the forest (Mitchell, 2015).
Relative frequency=(Absolute frequency (Species A))/(Frequency of all trees)*100
Absolute frequency=(Number of sampling point (Species A))/(Total sampling points)
The last aspect for importance value is relative density, which depicts the amount of species A throughout the forest (Mitchell, 2015).
Relative density=(Number of trees (Species A))/(Number of Trees)*100
The importance value calculated from the data collected will quantify the biodiversity found in Manor House wood lot by showing the amount of species measured and an estimate of their density, coverage, and frequency throughout the forest.